One time, I forgot Pryce existed. I was mentally running through all of the gym leaders, and I kept getting stuck at the 7th gym of Johto.
I doubt I'd forget Norman, especially after how tense my battle with him was in my first run of Sapphire. It came down to his second slaking, and a 15 levels under leveled Makuhita. I was lucky he kept using focus punch; Makuhita kept using Vital Throw to stop his punches. That battle really taught me not only that I couldn't rely on a single over leveled Pokémon always, and that priority is weird.